Absorption shim for freight car trucks



May 3o, 1933.

T. H. SYMINGTON ABSORPTION SHIM FOR FREIGHT CAR TRUCKS Filed sept. 2o, 1929 2 Sheets-Sheet l milf/44% May 30, 1933. T. H. sYMlNGToN l 1,911,330

BSORPTION'SHIM FOR FREIGHT CAR TRUCKS I Filed Sept. 20, 1929 2 Sheets-Sheet 2 aww/nbc) Patented May 30, 1933 l UNITED STATESN THOMAS H. SYEINGTON, OF BALTIMORE, MARYLAND, ASSIGNOB TO T. H. SYHINGTON- PATENT OFFICE & SON INC., OF BALTIMORE, MIARYLAND, CORPORATION OF MARYLAND ABSOBIPTION SHH FOB FREIGHT CAB TRUCKS Appueaaen mea september 2o, 1929. Semi ne. 394,023.

The invention relates to railway equipment, particularly to accessories ork attac ments for use `in connection with the trucks of freight cars.

It is of course well known that in the ordinary. truck construction the truck bolster extends within a window opening in the side frame and is supported'by a plurality of helical s rings which yieldingly support the load. yprings of this, or in fact any other type, have a certain natural period of vibration. It is also known that when a freight car is travelling over a track the passage of the truck wheels over the rail joints sets up certain impulses tendin to produce vibration. At certain speeds t ese impulses are synchronized with the natural period of vibration of the springs and the result is the development of a side sway of P the car particularly as the joints in the rails are staggered. When a rocking movement of the car and truck bolster develops, there is great compression of the springs beneath the bolster end which is moving downward ly. When a sway in the other direction takes place it has been found that the recoil is so strong that the rising end of the bol`. ster is thrown' clear o' from the sprmgs.

In a certain recent test of a car having a load of eighteen tons it was found that at certain diiierent speeds, particularly at about forty-'three and forty-eight miles per hour an amazing degree of vertical jiggle developed with the resulty thaton the recoil the bolster was thrown clear of the truck springs by as much as nine-sixteenths of an inch, there being, naturally, a tremendous hammer blow exerted whenthe ends of the bolster move .downwardly on the return. The shocks and jars resulting from this condition are very destructive to the equipment and particularly to the car lading.

It is with the above facts in view that I have devised the present invention which has yfor its general object the provision of au absorption means adapted to be interposed in the truck in series with the truck springs for cushioning the blow and absorbing the shocks upon the inevitable developfment of car jiggle under certain conditions of speed, etc. j An important object of the invention is to provide an absorption means inthe nature of a compressible or yieldable shim located preferably between the truck springs and the truck bolster and operating to take a large proportion of the shock so that the equipment itself and the lading vjwill be relieved. j f

A more specific object of the invention is to provide an absorption shim embodying an elastic cushion, preferably of rubber, together with the necessary metallic elements or the protection thereof, this shim being adapted for insertion between the truck bolster and the truck springs or spring cap. Yet another object of the invention is to rovide an absorption shim of this type in which the degree of compression is limited terial to a strain greater than that it is capable of withstanding.

o A still more specific object of the invention is to provide an absorption shim-like device embodying a combination of metallic and rubber elements so related that the lati strain without causing permanent distortion. s

Another object is to provide a device of Athis character having means for effecting centering or positioning thereof with respect to the spring nest.

An additional object Ais to provide a device of this character which may be modified for use in connection with spring nests of different sizes, depending upon the type of car and load capacity thereof and which will moreover be simple and inexpensive to make, easy 'to install, positive in action, eflicient 70 so as to avoid subjecting the yielding maand durable in service, and a general improvement in the art.

5 preferably consists in the details of construction and the arrangement and combination of parts to be hereinafter more fully described and claimed, and illustrated in the accompanying drawings in which:

Figure 1 is a vertical sectionalview taken across the side frame 4at one side of a car truck and showing the truck bolster in elevation with my device interposed between it and the spring nest,

Figure 2 is a plan view of the device alone with'one of the metal plates thereof broken away,

vFigure 3 is a vertical cross sectional view thergthrough taken on the line 3 3 of Figure Figure 4 is a plan view of the device showing a slight modification for use in connection wit cars of reater capacity, a portion of one metal p ate being broken awa v Flgure 5 .is a detail sectional view taken on the line 5-5 of Figure 2,

Figure 6 is a fragmentary elevation showina slight modiiication, Y

igure 7 is a detail cross section illustratinanother variation, I

' igure 8 is a similar view illustrating yet another form, l v

Figure 9 is a plan view similar to Figure 2 showing another modication, and

Figure l0 is a view similar to Fi ure l but showing the shim device locate in a dierent position.

Referring more particularly to the drawings it will be noted that I have shown a portion of a standard A. R. A. truck including a side frame l having a Window-o ening 2 through which extends one end o the truck bolster 3 which is ordinarily engaged .upon the spring cap 4 at the top of a nest o coil springs 5 which in turn rest upon the spring plank 6 which extends across the truck, there being another spring cap 7 interposed between the spring nest and the spring plank.

In accordance with my invention I interpose between the truck springs 5 and the bolster 3 a shock absorbin shim indicated as a whole y the numeral 8. In its broadest sense, this device coin-v prices, preferably, a rubber or equivalent cushion with `stop means for limiting the compression thereof. The invention is oi course capable of being carried out in various different specilic ways and I have cony 'Y sequently illustrated several modiications,

certain of which vary from others only in the matter of size and shapel to correspond to the size of the spring nest or number of springs therein, this in turndepending upon` E or cushioningthe capacity of the car, it being known that there are usually four'springs provided for j j a fifty ton truck Whereas there are five vfor-11 As shown in Figures l to 3, the shim device `8 preferably comprises a pair of, metal plates 9 between which are arranged symmetrically disfposed pads 10 of yieldable material, pre erabl rubber. The metal plates 9 are intende to conform substantially to the size and shape ofthe spring cap 4 and the rubber pads are not only spaced apart as shown, to permit lateral expansion in all directions, but are also preferably spaced inwardly from the yedges of the plates. The principal purpose of the metal plates is to prevent distortion and shaping of the rubber pads and loss of the stop means to be described and they need not, therefore, be of any great'thickness. Actually-these plates may very convenientl be stamped from sheet steel of, say, oneou hr mch or three eighths inch in thickness. he rubber pads are naturally several times thicker, the exact dimensions up to certain limits being more or less immaterial.

'lhe metal plates may be formed with cirl cular openings ll adapted to\receive the upstanding projections l2 customarily provided on the spring cap l and as these holes are provided in both plates Lthen the shim device is reversible. How ver, it such should be found desirable iler any reason, one plate may have such a hole ll'therein while the other plate, indicated at i3 in Figure d, may have projections lll thereon adapted to enter the openings l-custoniaril provided in the underside .of the truck bo ster for the reception ot' the rojections on the spring cap 4. As a rule, t e proiections on the spring cap extend outwardly about three-sighting, ol an inch and are conical in shape. ll the metal plates 9 have a thickn 'ness of three-'eighths of an inch, as may b preferable, then it would not be necessary to forni holes entirely therethrough as recesses, which might be made by means of a drill, would be entirely suiicient as clearly illustrated in Figure 5. The advantage of this thickness of metal plate 9 and a simple recess therein instead of a' hole is that the projection on the spring ca could not ac-4 tually contact with the rub r pad at this is located a in or block 17 of metal of a hei ht less tiian the thickness of the pads an of less diameter than the opening 16 so as to permit the rubber to ilow laterally under compression. The exact height of the pins or blocks 17 depends upon the maximum safe compressibility of the rubber.

In Figure 7 there is illustrated a modiication 1n which the metal plates 18, corresponding to the above described plates 9, are formed with inwardly extending projections 19 which may be readil formed stamping and which are locate opposite to and extend within the openings 16 in the rubber pads 10. Located within the opening in each rubber ad is a metal block-like member 20 of less ii between the 'inwardly extending projections 19 so as to permit compression of' the rubber pad while preventing over-compression thereof, the block member 20 being engaged by the confronting faces of `the projections 19 to effect the limited movement.

yFi ure 8 discloses yet another variation in w ich the metal plates 21 corresponding to the plates 9 and 18 are formed with holes 22 opposite the center of each rubber pad 10, these holes receiving the Shanks 23 of stop pins 24 located within the central opening-16 in each pad. The members 24 are preferably frusto-conical'in shape to permit flowing or crowding out of the rubber and the outer ends o the reduced Shanks 23 are upset to make a permanent mounting. rlhe members 24 are spaced apart a distance corresponding to the safe maximum compression travel of the rubber Ipads and when the pads have been com ressed to the maximum safe extent the mem ers 24 will engage and prevent further compression.

`Naturally the size of the metal plates and the number of rubber pads depends upon the character of the spring nest and s ring cap in the truck in which the shim evice is used and this in turn is governed by the capacity of the car.- -Figures 2 and 3 show the arrangement for cars ranging, say, from a capacit of forty to fifty-live ton trucks whereas igure 4 shows larger metal plates 25 and a. greater number of rubber pads such as would be necessary say for aseventy ton car. In every other respectthe construction may be the same, that is to say either the stop pins 17 shown in Figure 2 or the stop members 20 and 24 shown in Figures 7 and 8, respectively, may be employed, as the only difference is in the mattei* of Asize and number 4of pads. y

In the above described forms of the invention the rubber pads 10 are represented as of rectangular shape spaced apart a sufficient distance to permit the rubber to flow or crowd when compressed. However, there is no necessity for this particular shape and in fact it may be preferable to use pads of eight than the distance circular or cylindrical shape as shown at 25 in Figure 9, the corners of the confining metal plates 26 being preferably rounded off and substantially concentric with the corner pads. Itis also intended that the pads be spaced inwardly from the edges ofv the metallic plates as in the iirst .described forms and that they also be spaced apart to permit the lateral crowding out or flowing of the yrubber under compression. An advantage in employing the circular or cylindrical pads with the metallic stop elements, of any type desired, at the centers thereof is that there will be a uniform distance between the stop element and the outer edge of each pad at all points so that the lateral crowding out or ilow of material will be uniform.

In assembling the shim device, it is conceivable that the rubber pads might be vulcanized onto one or both of the metal plates though actually it is probably suilicient that they simpl; be shellacked or cemented in place for t e purpose of preventing dislocation of the parts and consequentlo'ss of the .stop members in case those "shown in Figures 3 and 7 are used, when the device is handled during transportation or at any itbetween the spring cap 4 and the underside of the truck bolster as\ shown in Figure 1 or between the bottom cap and the spring plank as shown in ligure 10. lThe pressure will then hold the parts against displacement so that no further reliance need be placed upon the shellac, cement or what other securing means The holes or recesses 11 in the lower plate member 9 will receive the upstanding projections 12 on the spring cap 4. If the top late be provided with corresponding projections, as shown at 14 in Figure` 6, then they will in Aturn be received within the openings 15 in the underside of the truck bolster.

In all forms of the invention, it is apparent that the operation will be the same, that is to say the rubber pads will be compressed, the degree of compression being vlimited either b the engagement of the top plate 9 with the stop pins 17 shown in Figures 2 and 3, by the engagement of the depressions 19 in the top plate with the blocks 20 as shown in Figure 7, or by engagement of the stop pins 24 shown 'in Figure 8. The shim device is of course in series with the truck springs regardless of whether it be placed above or below the nest. ',Vhen compression of the rubber pads occurs the rubber is permitted to flow or crowd laterally owing compared with the diameter of the stop pins,

blocks or other elements. The metallic stop might be provided. l

- ferred embodiments of members, regardless of which form is employed, willffoperateto prevent over-compression of and damage to the rubber. When a shim device of'this type is installed within". a truck it 'isi evidentthat it will absorb over-solid blows and relieve the mechanism of vexcessive strains vwhich. would otherwise come upon it. Another point of advantage is that the yieldable rubber pads will operate to smooth out small shocks and jars such as would not affect the springs to any material extent and will consequentlly improve the riding qualities of the car. urthermore as the rubber pads naturally have a different period of vibration from that of the helical springs which compose the spring nest it is evident that synchronism will be broken up and vertical Jiggle greatly reduced if not actually entirely eliminated. It will be noted that the construction is not only simple but extremely rugged and that in the event of any necessity or replacements the shim devices may be removed from the truck and equipped with new or fresh rubber pads. owever, this would not be necessary until after the expiration of ,a prolonged period. It is believed from the foregoing that the construction, operation and advantages will bev readily apparent to one skilled in the art without further explanation.

v While Ishave shown-'and described prethe invention, itv

`should be understood that the disclosure'is merely an exempliication of the principles involved as the right is reserved to make all Vsuch chan esin the details of construction y as will widen the field of utility and inf Acrease/the adaptability of the device'pro- *vided such :chan es constitute no departure' y f of ythefclaims hereunto L .Having thus describe theinvention or the f from' the spirit o aipended.

scope bolster andA supporting 'springs therefor, a

- vlaterally unco'ilned'yieldable cushion inter- ,withthes rin 50 P gs lllicontact withthefl tteran pjo'se'd betweentheffsprings and the bolster d acting in series f series with the springs, and means for limiting the compression of the cushion while permitting lateralv expansion in all\lirec tions. i'

3. In a railway car truck embodying a bolster and supporting springs therefor arranged in a nest, means disposed against a selected side of the vnest and operating in series therewith for absorbing shocks, said means embodying a laterally expansible rubber pad. y

4. In a railway car truck embodying a 4the compression of the pad.

the invention, I ya. truck lholster and the rftruck embodying a` tween and bers, .infer 4trucks comprising a shim structure ada ted `for interposition between the bolster an the supporting springs therefor and comprisa yieldable pad intering metallic plates,

'and means for limiting posed therebetween,

7. An absorption device for railway trucks comprising 1a shim structure ada ted for interposition between the bolster andp the supporting springs therefor and comprising metallic plates, a yieldable pad interposed therebetween, and ymeans for limiting the compression of the pad, said limiting means consisting of metallic elements interposed i in the pad and of less height than the thickness of the pad.

8.. An absorption shim device for insertion between a truck bolster and the supportingsprings therefor, comprising metallic plates, avrubber pad interposed therebetween,'stop `means for limiting the compression'. ofthe pad, the pad having openings vpermitting the material thereofvto flow or crowd in all lateral directions. v n v9. Anabsorption device of the character described adapted for interposition between supporting springs car therefor, comprising metallic plate members, 4

a yieldable` rubber pad interposed ,therebeformed with openings, and metallic stop elements located within said openings.` f y 10. Anv absorption device of the character kdescribed adapted for interpositionbetween O y y al truck bolster'and the supporting springs vvbolster and supporting sprig-thereforyayieldable cushion interposed',V between the springs and the spring plank and actinginj therefor, comprising metallic plate memaplurality of yieldable Arubber pads posed therebetween f and formed with openings, andgmetallic stop elements located within said openings andof less diameter thany the openings-to permit crowding of the material of the pad in all lateral directions. 11. An absorption device of the character described adapted for interposition between a truck bolster' and thefjsupporting springs therefor, comprising metallic plate members, a yieldable cushion interposed therebetween and comprising ad units formed with openings, and meta lic stop elements located rWithin said openings and of less diiso A.

/ rubber pads truck springs, comprising ameter than the openings to permit crowding of the material of thepad in all lateral directions, said metal plates being Vapertured y for the accommodation of the centering projections on the spring cap of the truck. 12. In a railway7 car truck,` the combination with the truck springs, device interposed in series therewith and comprising 'a pluralit of rubber pads coniined between metallic plate elements and containing compression limitin means. 13. In a railway car truck, t ev combination with the truck springs, of acushion interposed in series therewith and comprising metallic confining plates,

located therebetween and formed centrally with openings, and metallic stop elements located within the openings, said pads being of cylindrical form whereby they are capable of uniform lateral eapansion in all directions under compression. 14. An absorption shim adapted for interposition inl series with a nest of railway a pair of metal plates, a rubber pad interposed vbetween said plates, said pad being formed with an opening therethrough, and a metallic pin 1ocated within the opening and of less height than the thickness of thepad for limiting compression thereof.

of a cushioning the respective pads, said metallic elements being spaced apart but adapted to contact for limiting compression of the pads, said metallic elements being formed as rivetlike members having shanks passing through the plates and'having tapered heads.

In testimony whereof I aliix my signature.

THOMAS H. sYMiNGToN.

a plurality of 15. An absorption shim device adapted for interposition in series with a railway truck spring nest comprising a pair of metal plates with a plurality of rubber padsim terposed therebetween, Veach padbeing formed with an opening, and 'attached metallic elements proiecting inwardly from the projecting for inter i forA inte confronting faces of said plates and entering the openings in the respective pads, said metallic elements' being spaced apart but adapted to contact for, limiting compres-` y sion of the pads. 16. An absorption shim device adapted sition truck spring nest comprisin plates with a plurality of ru ber pads interposed therebetween, each pad being formed with an opening, spaced inwar y vfrom the confronting faces of said plates and enteri ings in the respective pads, an means in-A te between said elements and cooperating therewith for limiting compression of the pads, out from the material "of the plates.

17. An absorption him, device adapted 'tion vin truck spring nestfcomprising a pair of metal plates a plurality of rubber pads interposed therebetween, each pad being formed in series with a railway apair of metal metallic elements the opensaid metallic elements being struck J series with a railway with an opening, and metallic elements prol v aces ias 

